Merge pull request #11338 from rudkx/bail-on-too-complex

Remove -swift-version 3 checks for "expression too complex".

Author: rudkx

lib/Sema/CSSolver.cpp

@@ -1342,8 +1342,7 @@ ConstraintSystem::solve(Expr *&expr,
   // had found at least one solution before deciding an expression was
   // "too complex". Maintain that behavior, but for Swift > 3 return
   // Unsolved in these cases.
-  auto tooComplex = getExpressionTooComplex(solutions) &&
-    !getASTContext().isSwiftVersion3();
+  auto tooComplex = getExpressionTooComplex(solutions);
   auto unsolved = tooComplex || solutions.empty();
 
   return unsolved ? SolutionKind::Unsolved : SolutionKind::Solved;
@@ -1876,9 +1875,7 @@ bool ConstraintSystem::solveSimplified(
   // not allow our caller to continue as if we have been successful.
   // Maintain the broken behavior under Swift 3 mode though, to avoid
   // breaking code.
-  auto tooComplex = getExpressionTooComplex(solutions) &&
-    !getASTContext().isSwiftVersion3();
-
+  auto tooComplex = getExpressionTooComplex(solutions);
   return tooComplex || !lastSolvedChoice;
 }
 

test/Misc/expression_too_complex.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -solver-memory-threshold 12000 -propagate-constraints
+// RUN: %target-typecheck-verify-swift -solver-memory-threshold 16000 -propagate-constraints
 
 var z = 10 + 10 // expected-error{{expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions}}